1. Technical Field
The present invention relates to the field of vehicles and more particularly to the drivetrain of vehicles.
2. Description of Related Art
An automotive vehicle employing an internal combustion engine generally uses a throttle to control the acceleration of the vehicle. In most vehicles when the engine is throttled up, the rate of delivery of power supplied by the engine is increased causing an increase in force transmitted through the drivetrain to the wheels of the vehicle causing the vehicle to accelerate. Alternatively when the engine is throttled down, a reduction in force is transmitted through the drivetrain to the wheels of the vehicle causing deceleration at least in part due to engine braking.
Engine braking is known to negatively affect the vehicle's drivetrain and can be a significant force and stress to the engine. It not only causes stress in the drivetrain components by subjecting them to forces in a direction opposite to that for which they may have been engineered, but engine braking may also reduce the stability of the vehicle among other negative consequences. Particularly with high-compression, large displacement four-stroke racing engines, the detriments caused by engine braking are appreciated by those skilled in the art.
For example when a vehicle is racing particularly on a track, the vehicle is subject to abrupt downshifting at high speeds upon approaching and entering a corner or curve of the track. The abrupt downshifting is typically executed before entering the turn. This is done to preclude upsetting the balance of the vehicle caused by depressing and releasing the clutch for a lower gear while turning. Downshifting allows the vehicle to have power by being in a lower gear as soon as possible to exit the turn.
However, this creates a problem when exiting the turn because unless the driver has revved the engine while the clutch is depressed, releasing the clutch after shifting to the lower gear will cause the torque from the decelerating engine to be transmitted to the rear wheels. Such an action may tend to cause the rear wheels to briefly lock up and will have the effect of additional braking from the rear wheels. This can be very upsetting to the balance of the car particularly if it occurs in a turn and may cause the driver to loose control.
One technique used to try and eliminate these problems is heel-and-toe braking. Heel-and-toe braking is when the driver manipulates the throttle and the brake at the same time with the right foot. The idea is that when entering a turn and downshifting at the same time, the revolutions of the engine should be to deter having the driving wheels lock up and/or lose traction. Heel-and-toe braking allows the driver to brake, shift, and set up for the turn, all without locking up the tires or offsetting the vehicle's balance. However heel-and-toe braking is difficult to master. For example, when too little throttle is applied, the nose of the vehicle will dive once the clutch is released, causing an oversteer situation or, in the case of the front wheels locking, an understeer situation. If too much throttle is applied, the vehicle will accelerate towards the turn, causing the entrance of the turn to be missed.
What is needed is an apparatus that can easily be attached to a vehicle to prevent torque from a decelerating engine from being transmitted to the wheels of the vehicle and prevent upsetting the vehicle's balance when downshifting. The apparatus should be easy to install, not harm the vehicle, or cause excessive wear on the vehicle. It would be beneficial if the apparatus could be relatively easy to engage or disengage.